The Chorus representation is a sparse, similarity-preserving representation achieved by a feedforward neural network. Hence it is probably better suited for interpolation than for categorization. This commentary raises the question of how to combine categorization with interpolation, whether feedforward networks can be reasonable models for parts of the cerebral cortex, and whether people can perform more than one interpolation at a time.

We briefly review the long-standing ideas about the use of synchronicity in the brain, which rely on Donald Hebb's views on cell assemblies and synaptic plasticity. More recently the distinction among several timescales in the description of neural activity has become a focus of theoretical discussion. Phillips & Singer's target article is criticized mainly because it does not distinguish these timescales properly and hence does not really address the questions so intensely debated today.